In-line electron beam test system

ABSTRACT

A method and apparatus for testing a plurality of electronic devices formed on a large area substrate is described. In one embodiment, the apparatus performs a test on the substrate in one linear axis in at least one chamber that is slightly wider than a dimension of the substrate to be tested. Clean room space and process time is minimized due to the smaller dimensions and volume of the system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/375,625 (Attorney Docket No. 010191US), filed Mar. 14, 2006, whichclaims benefit of U.S. Provisional Patent Application No. 60/676,558,filed Apr. 29, 2005, both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a test systemfor substrates. More particularly, the invention relates to anintegrated testing system for large area substrates in the production offlat panel displays.

2. Description of the Related Art

Flat panel displays, sometimes referred to as active matrix liquidcrystal displays (LCD's), have recently become commonplace in the worldas a replacement for the cathode ray tubes of the past. The LCD hasseveral advantages over the CRT, including higher picture quality,lighter weight, lower voltage requirements, and low power consumption.The displays have many applications in computer monitors, cell phonesand televisions to name but a few.

One type of active matrix LCD includes a liquid crystal materialsandwiched between a thin film transistor (TFT) array substrate and acolor filter substrate to form a flat panel substrate. The TFT substrateincludes an array of thin film transistors, each coupled to a pixelelectrode and the color filter substrate includes different color filterportions and a common electrode. When a certain voltage is applied to apixel electrode, an electric field is created between the pixelelectrode and the common electrode, orienting the liquid crystalmaterial to allow light to pass therethrough for that particular pixel.

A part of the manufacturing process requires testing of the flat panelsubstrate to determine the operability of pixels. Voltage imaging,charge sensing, and electron beam testing are some processes used tomonitor and troubleshoot defects during the manufacturing process. In atypical electron beam testing process, TFT response within the pixels ismonitored to provide defect information. In one example of electron beamtesting, certain voltages are applied to the TFT's, and an electron beammay be directed to the individual pixel electrodes under investigation.Secondary electrons emitted from the pixel electrode area are sensed todetermine the TFT voltages.

The size of the processing equipment as well as the process throughputtime is a great concern to flat panel display manufacturers, both from afinancial standpoint and a design standpoint. Current flat panel displayprocessing equipment generally accommodates large area substrates up toabout 2200 mm by 2500 mm and larger. The demand for larger displays,increased production and lower manufacturing costs has created a needfor new testing systems that can accommodate larger substrate sizes andminimize clean room space.

Therefore, there is a need for a test system to perform testing on largearea substrates that minimizes clean room space and reduces testingtime.

SUMMARY OF THE INVENTION

The present invention generally provides a method and apparatus fortesting electronic devices on a substrate that performs a testingsequence by moving the substrate under a beam of electrons from aplurality of electron beam columns. The plurality of electron beamcolumns form a collective test area adapted to test the entire width orlength of the substrate. The substrate is moved relative the test areain one direction until the entire substrate has been subjected to thebeam of electrons. A testing chamber is disclosed that may be coupled toone or more load lock chambers, or the testing chamber may also functionas a load lock chamber.

In one embodiment, an apparatus for testing electronic devices on alarge area substrate is described. The apparatus includes a testingplatform having a substrate support disposed thereon, an end effectormovably disposed in the substrate support, and one or more testingcolumns coupled to the testing platform, each testing column having anoptical axis and a test area, wherein the substrate is movable in asingle axis and the single axis is orthogonal to the optical axis of theone or more testing columns, and wherein a collective test area of thetesting columns is configured to cover an entire width or an entirelength of the substrate such that the testing columns are capable oftesting the entire substrate as the substrate is moved through theapparatus along the single axis.

In another embodiment, an apparatus for testing electronic deviceslocated on a large area substrate is described. The apparatus includes atesting platform having a support surface for supporting a large areasubstrate, a prober coupled to the testing platform, and a plurality oftesting columns coupled to the testing platform in a first lineardirection, each of the plurality of testing columns having an opticalaxis within a test area, wherein the substrate is movable in a secondlinear direction that is orthogonal to the optical axis and theplurality of testing columns have a collective test area sufficient totest an entire width or an entire length of the substrate such that thetesting columns are capable of testing the entire substrate as thesubstrate is moved in the linear direction through the apparatus.

In another embodiment, a system for testing electronic devices locatedon a large area substrate is described. The system includes a testingplatform, a substrate support disposed on the testing platform, thesubstrate support sized to receive a large area substrate, an endeffector disposed within the substrate support adapted to move thesubstrate relative to the substrate support, a prober support coupled tothe substrate support, and a plurality of testing devices coupled to anupper surface of the testing platform, each of the plurality of testingdevices having a test area, wherein the plurality of testing devices arespaced to form a collective test area sufficient to test an entirelength or an entire width of the substrate such that the testing devicesare capable of testing the entire substrate as the substrate is moved ina single direction through the system.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is one embodiment of a test system.

FIG. 2 shows another embodiment of a test system.

FIG. 3 is a schematic plan view of one embodiment of a substratesupport.

FIG. 4 is a perspective view of another embodiment of a substratesupport.

FIG. 5 is one embodiment of a testing column.

FIG. 6 is another embodiment of a test system.

FIG. 7 another embodiment of a test system.

FIG. 8A is one embodiment of a prober.

FIG. 8B is a cross-sectional view of one embodiment of a structuralmember.

FIG. 8C is a cross-sectional view of another embodiment of a structuralmember.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

The term substrate as used herein refers generally to large areasubstrates made of glass, a polymeric material, or other substratematerials suitable for having an electronic device formed thereon.Embodiments depicted in this application will refer to various drives,motors and actuators that may be one or a combination of the following:a pneumatic cylinder, a hydraulic cylinder, a magnetic drive, a stepperor servo motor, a screw type actuator, or other type of motion devicethat provides vertical movement, horizontal movement, combinationsthereof, or other device suitable for providing at least a portion ofthe described motion.

Various components described herein may be capable of independentmovement in horizontal and vertical planes. Vertical is defined asmovement orthogonal to a horizontal plane and will be referred to as theZ direction. Horizontal is defined as movement orthogonal to a verticalplane and will be referred to as the X or Y direction, the X directionbeing movement orthogonal to the Y direction, and vice-versa. The X, Y,and Z directions will be further defined with directional insetsincluded as needed in the Figures to aid the reader.

FIG. 1 is an isometric view of one embodiment of an in-line test system100 adapted to test the operability of electronic devices located onlarge area flat panel substrates, for example, the large area substrateshaving dimensions up to and exceeding about 2200 mm by about 2600 mm.The test system 100 includes a testing chamber 110, one or more loadlock chambers 120A, 120B, and a plurality of testing columns 115 (sixare shown in FIG. 1), which may be electron beam columns or any deviceadapted to test electronic devices located on large area substrates,such as thin film transistors (TFT's). The test system 100 is typicallylocated in a clean room environment and may be part of a manufacturingsystem that includes substrate handling equipment such as roboticequipment or a conveyor system that transports one or more large areasubstrates to and from the testing system 100.

The one or more load lock chambers 120A may be disposed adjacent andconnected to the testing chamber 110 on one side, or on both sides ofthe testing chamber 110 by a valve 135A disposed between load lockchamber 120A and the testing chamber 110, and a valve 135B disposedbetween load lock chamber 120B and the testing chamber 110. The loadlock chambers 120A, 120B facilitate transfer of large area substrates toand from the testing chamber 110 and ambient environment from a transferrobot and/or a conveyor system typically located in the clean roomenvironment. In one embodiment, the one or more load lock chambers 120A,120B may be a dual slot load lock chamber configured to facilitatetransfer of at least two large area substrates. Examples of a dual slotload lock chamber is described in U.S. Pat. No. 6,833,717, which issuedDec. 21, 2004, and U.S. patent application Ser. No. 11/298,648, filedJun. 6, 2005, and published as United States Patent Publication No.2006/0273815 on Dec. 7, 2006, both of which are incorporated herein byreference to the extent the applications are not inconsistent with thisdisclosure.

In one embodiment, the load lock chamber 120A is adapted to receive thesubstrate from the clean room environment through an entry port 130A,while the load lock chamber 120B has an exit port 130B that selectivelyopens to return the large area substrate to the clean room environment.The load lock chambers 120A, 120B are sealable from ambient environmentand are typically coupled to one or more vacuum pumps 122, and thetesting chamber 110 may be coupled to one or more vacuum pumps 122 thatare separate from the vacuum pumps of the load lock chambers 120A, 120B.An example of various components of an electron beam test system fortesting large area substrates are described in U.S. Pat. No. 6,833,717which issued Dec. 21, 2004, and was previously incorporated byreference.

In one embodiment, the test system 100 includes a microscope 158 coupledto the test system to view any areas of interest encountered on thelarge area substrate. The microscope 158 is shown attached to amicroscope assembly 160 that, in one embodiment, is coupled to the loadlock 120A, while alternative embodiments (not shown) may couple themicroscope 158 and microscope assembly 160 to one or both of the testingchamber 110 and the load lock chamber 120B. The microscope assembly 160includes a gantry 164 which facilitates movement of the microscopeassembly 160 above a transparent portion 162 on the upper surface of theload lock chamber 120. The transparent portion 162 may be fabricatedfrom a transparent material such as glass, quartz, or other transparentmaterial designed to withstand heat, negative pressure, and otherprocess parameters.

The gantry 164 is configured to provide at least X and Y movement to themicroscope assembly 160 to view the areas of interest on the large areasubstrate disposed in the load lock chamber 120 through the transparentportion 162. For example, the microscope 158 can move in the X and Ydirections to a particular coordinate on the large area substrate, andmay also move in the Z direction above the large area substrate disposedin the load lock chamber 120. A controller (not shown) may be coupled tothe testing system 100 and the microscope assembly 160 to receive inputof areas of interest located by the testing columns 115 on the largearea substrate and provide coordinates to the microscope assembly 160.In one embodiment (not shown), the microscope assembly may be coupled tothe testing chamber 110 adjacent the testing columns 115 and configuredto move in at least the X direction parallel to the plurality of testingcolumns 115. In this embodiment, the testing chamber 110 includes atransparent portion on at least a portion of the upper surface of thetesting chamber 110, and the gantry 164 and microscope assembly 160 maybe coupled to the upper surface of the testing chamber 110 to view areasof interest on the large area substrate when disposed in the testingchamber 110.

In one embodiment, the test system 100 is configured to transport alarge area substrate 105 having electronic devices located thereonthrough a testing sequence along a single directional axis, shown in theFigure as the Y axis. In other embodiments, the testing sequence mayinclude a combination of movement along the X and Y axis. In otherembodiments, the testing sequence may include Z directional movementprovided by one or both of the testing columns 115 and a movablesubstrate support within the testing chamber 110. The substrate 105 maybe introduced into the test system 100 along either the substrate widthor substrate length. The Y directional movement of the substrate 105 inthe test system allows the system dimensions to be slightly larger thanthe width or length dimensions of the substrate 105.

The test system 100 may also include a movable substrate support tableconfigured to move in at least a Y direction through the test system100. Alternatively, the substrate 105, with or without a support table,may be transferred through the test system by a conveyor, a belt system,a shuttle system, or other suitable conveyance adapted to transport thesubstrate 105 through the test system 100. In one embodiment, any ofthese support and/or transfer mechanisms are configured to only movealong one horizontal directional axis. The chamber height of the loadlocks 120A, 120B, and the testing chamber 110 can be minimized as aresult of the unidirectional transport system. The reduced heightcombined with the minimal width of the testing system provides a smallervolume in the load locks 120A, 120B, and the testing chamber 110. Thisreduced volume decreases pump-down and vent time in the load lockchambers 120, 125, and the testing chamber 110, thereby enhancingthroughput of the test system 100. The movement of the support tablealong a single directional axis may also eliminate or minimize thedrives required to move the support table in the X direction.

FIG. 2 is another embodiment of an electron beam test system 100 havinga testing chamber 210 that also functions as a load lock chamber. Inthis embodiment, the testing chamber 210 is selectively sealed fromambient environment by valves 135A, 135B, and is coupled to a vacuumsystem 122 designed to provide negative pressure to the interior of thetesting chamber 210. Each of the valves 135A, 135B have at least oneactuator 220 to open and close the valves when needed. A proberexchanger 300 is positioned adjacent the testing chamber 210 andfacilitates transfer of one or more probers 205 into and out of thetesting chamber 210. The one or more probers 205 enter and exit thetesting chamber 210 through a movable sidewall 150 coupled to thetesting chamber 210. The movable sidewall 150 is configured toselectively open and close using one or more actuators 151 coupled tothe movable sidewall 150 and a frame portion of the testing chamber 210.In addition to facilitating prober transfer, the movable sidewall 150also facilitates access and maintenance to the interior of the testingchamber 210.

When the one or more probers 205 are not in use, the one or more probers205 may be housed in a prober storage area 200 below the testing chamber210. The prober exchanger 300 includes one or more movable shelves 310A,310B that facilitate transfer of the one or more probers 205 into andout of the testing chamber 210. In other embodiments, the one or moreprobers 205 may be stored in other areas adjacent or coupled to thetesting chamber 210.

In one embodiment, the movable sidewall 150 is of a length that spanssubstantially a length of the testing chamber 210. In other embodiments,the movable sidewall 150 is shorter than the length of the testingchamber 210 and is configured to allow sufficient space for one or moreload lock chambers coupled to a side or length of the testing chamber210. In yet another embodiment, the movable sidewall 150 is not used, atleast for prober transfer, and the prober transfer is employed throughan upper surface of the testing chamber 210.

A detailed description of a prober exchanger and movable sidewall can befound in the description of the Figures in United States PatentPublication No. 2006/0273815, which was previously incorporated byreference. An example of a prober suitable for use in the test system100 is described in U.S. patent application Ser. Nos. 10/889,695, filedJul. 12, 2004 and issued as U.S. Pat. No. 7,319,335 on Jan. 15, 2008,and 10/903,216, filed Jul. 30, 2004, which issued as U.S. Pat. No.7,355,418 on Apr. 8, 2008, which applications are both incorporatedherein by reference to the extent the applications are consistent withthe disclosure.

FIG. 3 shows a schematic plan view of one embodiment of a substratesupport 360 that is configured to be housed within the interior volumeof the testing chamber 210, the testing chamber not shown for clarity.In one embodiment, the substrate support 360 is a multi panel stagewhich includes a first stage, a second stage, and third stage. The threestages are substantially planar plates, and are stacked on one anotherand, in one aspect, independently move along orthogonal axes ordimensions by appropriate drives and bearings. For simplicity and easeof description, the first stage will be further described below asrepresenting the stage that moves in the X direction and will bereferred to as the lower stage 367. The second stage will be furtherdescribed below as representing the stage that moves in the Y directionand will be referred to as the upper stage 362. The third stage will befurther described below as representing the stage that moves in the Zdirection and will be referred to as the Z-stage 365.

The substrate support 360 may further include an end effector 370. Inone embodiment, the end effector 370 includes a plurality of fingersthat rests on an upper surface of the upper stage 362 having a planar orsubstantially planar upper surface on which the substrate 105 may besupported. In one embodiment, the end effector 370 has two or morefingers connected at least on one end by a support connection 369. Thesupport connection 369 is adapted to couple each of the fingers to allowall of the fingers to move simultaneously. Each finger of the endeffector 370 may be separated by a slot or space within the Z stage 365.The actual number of fingers is a matter of design and is well withinthe skill of one in the art to determine the appropriate number offingers needed for the size of substrate to be manipulated.

For example, the end effector 370 can have four fingers 371A, 371B,371C, and 371D that are evenly spaced, which contact and support thesubstrate 105 when placed thereon. The end effector 370 is configured toextend out of the testing chamber to retrieve or deposit the substrateto and from a load lock chamber (FIG. 1), or to and from an atmospherichandling system, such as a transfer robot or conveyor system. Thefingers 371A-371D move in and out of the Z-stage 365 such that thefingers 371A-371D interdigitate with the segments 366A, 366B, 366C,366D, and 366E when the end effector 370 is disposed in substantiallythe same plane as the Z-stage 365. This configuration allows the endeffector 370 to freely extend and retract from the substrate support 360to the load lock chamber or atmospheric handling system. When retracted,the Z-stage 365 is adapted to elevate above the end effector 370 toplace the substrate 105 in contact with the planar Z-stage 365. Adetailed description of a multi panel stage can be found in thedescription of the Figures in U.S. Pat. No. 6,833,717 (previouslyincorporated by reference), and U.S. patent application Ser. No.11/190,320, filed Jul. 27, 2005 and published as United States PatentPublication No. 2006/0038554 on Feb. 23, 2006, which is incorporatedherein by reference to the extent the application is not inconsistentwith this disclosure.

FIG. 4 is a perspective view of a portion of the substrate support 360configured to be housed within the testing chamber, the testing chambernot shown for clarity. The fingers 371C, 371D of the end effector areshown in a retracted position above the Z stage 365. A prober 205 isshown in a transfer position above the Z stage 365 supported by a proberpositioning assembly 425. The prober positioning assembly 425 includestwo prober lift members 426 disposed on opposing sides of the substratesupport 360 (only one is shown in this view). The prober lift members426 are coupled to a plurality of Z-motors 420 at each corner of thesubstrate support 360 (only one is shown in this view). In thisembodiment, the Z-drive 420 is coupled to the substrate support 360adjacent a prober support 430. The prober 205 also has at least oneelectrical connection block 414 that is in electrical communication witha plurality of prober pins (not shown) that are adapted to contactdevices located on the large area substrate. The prober support 430 alsoprovides an interface for the electrical connection block 414 of theprober 205 via a contact block connection 474 that is appropriatelyconnected to a controller.

One side of the prober positioning assembly 425 is shown in FIG. 4having a plurality of friction reducing members coupled to the proberlift member 426. The friction reducing members are adapted to facilitatetransfer of the prober 205 by movably supporting an extended member 418of the prober frame 410. In this embodiment, the prober lift member 426includes a channel 427 adapted to receive the extended member 418 of theprober frame 410. The plurality of friction reducing members in thisembodiment are upper roller bearings 450 and lower roller bearings 460coupled to the prober lift member 426 adjacent the channel 427. Thelower roller bearings 460 support the extended member 418 and the upperroller bearings 450 act as a guide for the extended member 418 duringtransfer of the prober frame 410. Also shown is a locating member 416integral to the prober 205 adapted to seat in a corresponding receptacle422 integral to the prober support 430 in order to facilitate alignmentand support of the prober 205 when positioned on the prober support 430.

In operation, a large area substrate may be supported by the fingers371C, 371D of the end effector and the Z stage is actuated in a Zdirection to place the substrate on an upper surface thereof. The prober205 is transferred into the testing chamber 110, 210 from the proberexchanger 300 (FIG. 2). The prober 205 is transferred laterally from theprober exchanger 300 onto the prober positioning assembly 425, whereinlateral movement of the prober 205 ceases when the prober frame 410contacts a stop 425. The Z drive 420, coupled to the prober positioningassembly by a shaft 423, may then be lowered in the Z direction to placethe prober pins (not shown) in contact with selected areas or deviceslocated on the large area substrate. Once the prober 205 is in contactwith the substrate, the substrate support 360 is free to begin a testingsequence by moving the large area substrate supported thereon under thetesting columns 115.

In an exemplary testing operation in reference to FIGS. 1-4, the largearea substrate 105 is introduced into the load lock chamber 120A from asubstrate handling system that could be a conveyor system or a transferrobot. The load lock chamber 120A is sealed and pumped down to asuitable pressure by the vacuum pump 122. The valve 135A is then openedand the substrate is transferred to the testing chamber 110 by extensionand retraction of the end effector 370. With reference to any of theembodiments described herein, the large area substrate may be unloadedfrom either end of the system. For example, a large area substrate mayenter through one end of the system and exit an opposing end, or enterand exit through the same end.

A prober 205, configured to provide or sense a signal to or from thedevices located on the large area substrate, may be introduced through amovable sidewall 150 from the prober exchanger 300 adjacent the testsystem 100. Alternatively, the prober 205 may be transferred to the loadlock chamber 120A and coupled to the substrate 105 in the load lockchamber 120A, or coupled to the substrate prior to transfer into theload lock chamber 120A. As another alternative, the testing system 100may comprise a movable table that includes an integrated prober that iscoupled to the substrate throughout the travel path through the testsystem 100.

FIG. 5 is one embodiment of a testing column 115 that is an electronbeam column having an optical axis 510. In one embodiment, the opticalaxis 510 is the longitudinal axis of each testing column 115 andgenerally includes a center region of a test area 500 on the substrate105. Each testing column 115 is configured to produce a test area 500that may be defined as the address area or addressable quality area ofthe beam of electrons generated by the electron beam column on thesubstrate 105. In one embodiment, the test area 500 each electron beamcolumn produces on the substrate 105 is between about 230 mm to about270 mm in the Y direction and about 340 mm to about 380 in the Xdirection.

In another embodiment, the test area 500 is between about 240 mm toabout 260 mm in the Y direction, for example about 250 mm, and about 350mm to about 370 mm in the X direction, for example about 360 mm. In thisembodiment, adjacent testing columns 115 may have an overlap in testarea between about 0.001 mm to about 2 mm, for example about 1 mm, ormay have no overlap, wherein the test areas of adjacent beams areadapted to touch with no overlap. In another embodiment, the test area500 of each testing column is between about 325 mm to about 375 mm inthe Y direction and about 240 mm to about 290 mm in the X direction. Forexample, the test area 500 is about 345 mm in the Y direction, and about270 mm in the X direction.

In another embodiment, the collective test area is between about 1950 mmto about 2250 mm in the X direction and about 240 mm to about 290 mm inthe Y direction. In another embodiment, the collective test area isbetween about 1920 mm to about 2320 mm in the X direction and about 325mm to about 375 mm in the Y direction. In one embodiment, adjacenttesting columns 115 may have an overlap in test area ranging betweenabout 0.001 mm to about 2 mm, for example about 1 mm. In anotherembodiment, the test areas of adjacent testing columns 115 may notoverlap.

Once the substrate 105 has been introduced into the testing chamber 110with a prober connected thereto, the testing chamber 110 may be sealedand pumped down. Each of the testing columns 115 are configured to emita beam of electrons directed toward the substrate. In thisconfiguration, the plurality of testing columns 115 provide a collectivetest area that is adapted to test the entire width or length of thesubstrate as the substrate is moved under the testing columns. In oneembodiment, a substrate 105 is provided to the test system 100lengthwise and six testing columns 115 may be used to test the entirewidth of the substrate as the substrate is moved through the system. Inanother embodiment, the substrate 105 is provided to the test system 100widthwise and eight testing columns 115 may be used to test the entirelength of the substrate as the substrate is moved through the system.The invention is not limited to the number of testing columns disclosedand the actual number may be more or less depending on substrate sizeand test area formed on the substrate by the electron beam or beams. Thestaggered configuration of testing columns 115 shown in FIGS. 1 and 2produce test areas on the substrate that are adjacent and may partiallyoverlap, at least in the X direction, to allow each pixel on thesubstrate to be subjected to the beam of electrons during testing in onedirectional axis.

FIG. 6 is another embodiment of a testing chamber 110 having a pluralityof testing columns 115 coupled to the testing chamber 110 in a straightline configuration. This straight line configuration of the plurality oftesting columns 115 provides a collective test area sufficient to test alength or width of a large area substrate as the substrate is movedthrough the system. Although eight testing columns are shown, otherembodiments may require more or less, depending on process requirements.

The substrate 105 may be in continuous motion during testing, or thesubstrate may be moved incrementally during the test sequence. In eithercase, the entire substrate 105 may be tested in one travel path in thetesting chamber 110. Once the testing sequence is complete, the testingchamber 110 may be vented, the prober transferred out of the testingchamber, and the substrate 105 may be transferred to the load lockchamber 120A, 120B, for subsequent return to ambient environment. In theembodiments depicted in FIGS. 2 and 6, the substrate 105 may be returnedto ambient environment without transfer to a load lock chamber.

FIG. 7 is another embodiment of a test system 700. The test systemcomprises a testing chamber 710 having a plurality of testing columns115 and one or more side portions 705, 706, 707, and 708. The one ormore of the side portions 705, 706, 707, and 708 are configured tocouple to one or more load lock chambers 120A-120D, which are shown inphantom coupled to the chamber 710 in order to show the adaptability tovarious substrate travel paths. The various configurations and substratetravel paths using the one or more load lock chambers 120A-120D coupledto the chamber 710 are adaptations to the test system 700 to conserveclean room space and conform to varied clean room work flow paths

In one embodiment, the one or more load lock chambers 120A-120D maydefine a “T” configuration wherein a large area substrate is transferredinto and out of the testing chamber 710 through the one or more loadlock chambers 120A-120D. For example, the large area substrate may betransferred from the ambient environment of the clean room into the loadlock chamber 120A and then transferred back to ambient environment outof the load lock chamber 120B after a testing sequence.

In another embodiment, the one or more load lock chambers 120A-120D maydefine a “U” configuration wherein a large area substrate is transferredinto and out of the one or more load lock chambers 120A-120D. Forexample, the large area substrate may be transferred from the ambientenvironment in the clean room into the load lock chamber 120A and thentransferred back to ambient environment from the load lock chamber 120Cafter a testing sequence.

In another embodiment, the one or more load lock chambers 120A-120D maydefine a “Z” configuration wherein a large area substrate is transferredinto and out of the one or more load lock chambers 120A-120D. Forexample, the large area substrate may be transferred from the ambientenvironment in the clean room into the load lock chamber 120A and thentransferred back to ambient environment from the load lock chamber 120Dafter a testing sequence.

In the embodiments showing the T, U, and Z configurations of the one ormore load lock chambers 120A-120D, the one or more load lock chambers120A-120D may be a single slot load lock, or a dual slot load lockchamber as described above. The dual slot configuration facilitatestransfer of an untested large area substrate to the testing chamber andtransfer of a tested large area substrate to ambient environment. Themovable sidewall may be adapted to allow space for the one or more loadlock chambers coupled to one or more of the side portions 705, 706, 707,and 708. The side portions 705, 706, 707, and 708 may have valves (notshown) between the one or more load lock chambers 120A-120D tofacilitate transfer of the large area substrate therebetween. In oneembodiment, a prober exchange sequence may be provided by the proberexchanger as described above. In other embodiments, the prober exchangemay be provided through an upper portion of the testing chamber, or oneor more probers may be coupled to the large area substrate in one ormore of the one or more load lock chambers.

FIG. 8A is one embodiment of a prober 205 having a rectangular proberframe 410 configured to provide or sense a signal from the deviceslocated on the large area substrate. In one embodiment, the rectangularprober frame 410 is configured to cover a perimeter of the large areasubstrate having a dimension equal to or greater than the large areasubstrate and includes a plurality of structural members 411. In thismanner, the prober 205 provides a line of sight access or view of atleast a center portion of the large area substrate and the electronicdevices located thereon. In another embodiment, the prober 205 mayinclude one or more prober bars 810 disposed within, and betweenparallel portions of, the prober frame 410. The one or more prober bars810 may be fixed or movable within the prober frame 410. In thisembodiment, the one or more prober bars 810 and frame 410 are positionedabove the substrate such that minimal or no portions of a primary beamof electrons from the testing columns are covered by the prober frame,and/or minimal or no portions of the secondary electrons are obscured bythe prober bars. In this manner, the obscuring of the primary beam orsecondary electrons, or the “shading” effect over portions of the largearea substrate, is minimized or non-existent.

FIGS. 8B and 8C are cross-sectional views of embodiments of a structuralmember 805 and 806, respectively. The structural members 805 and 806 arecross-sectional views of the structural members 411 of the prober frame,and/or a cross-sectional view of the one or more prober bars 810. In oneembodiment, the structural members 805, 806 have two major sides and atleast one minor side, and at least one of the two major sides isslanted. The slanted portion is configured to provide an unobstructedbeam path 802, which may be a primary beam path and/or a secondaryelectron beam path. In other embodiments, the structural members 805,806 are polygons in a shape to provide rigidity and minimize the shadingeffect. Examples of structural shapes that provide rigidity and minimizethe shading effect are triangles, trapezoids, a trapezoid having oneright angle, or combinations thereof.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. An apparatus for testing electronic devices on a large areasubstrate, comprising: a testing platform having a substrate supportdisposed thereon; an end effector movably disposed in the substratesupport; and one or more testing columns coupled to the testingplatform, each testing column having an optical axis and a test area,wherein the substrate is movable in a single axis and the single axis isorthogonal to the optical axis of the one or more testing columns, andwherein a collective test area of the testing columns is configured tocover an entire width or an entire length of the substrate such that thetesting columns are capable of testing the entire substrate as thesubstrate is moved through the apparatus along the single axis.
 2. Theapparatus of claim 1, wherein the substrate support is movable relativeto the testing platform.
 3. The apparatus of claim 1, wherein thesubstrate support is housed in a testing chamber and the testing chamberis coupled to a vacuum pump.
 4. The apparatus of claim 1, wherein theone or more testing columns comprise an electron beam column.
 5. Theapparatus of claim 1, further comprising: a prober coupled to thesubstrate support.
 6. The apparatus of claim 5, wherein the proberfurther comprises a frame having at least one dimension that is largerthan a dimension of the substrate.
 7. The apparatus of claim 5, whereinthe prober further comprises on or more prober bars.
 8. The apparatus ofclaim 1, wherein the one or more testing columns includes six or moretesting columns.
 9. The apparatus of claim 8, wherein the six or moretesting columns are in a substantially straight line above the substratesupport.
 10. An apparatus for testing electronic devices located on alarge area substrate, comprising: a testing platform having a supportsurface for supporting a large area substrate; a prober coupled to thetesting platform; and a plurality of testing columns coupled to thetesting platform in a first linear direction, each of the plurality oftesting columns having an optical axis within a test area, wherein thesubstrate is movable in a second linear direction that is orthogonal tothe optical axis and the plurality of testing columns have a collectivetest area sufficient to test an entire width or an entire length of thesubstrate such that the testing columns are capable of testing theentire substrate as the substrate is moved in the linear directionthrough the apparatus.
 11. The apparatus of claim 10, wherein thetesting platform comprises: a substrate support.
 12. The apparatus ofclaim 11, wherein the substrate support comprises an end effectormovably disposed therein.
 13. The apparatus of claim 10, wherein thetesting platform comprises a prober support having the prober disposedthereon.
 14. The apparatus of claim 10, wherein the testing platform iswithin a testing chamber and the testing chamber is coupled to a vacuumpump.
 15. The apparatus of claim 10, wherein the prober furthercomprises a frame having at least one dimension that is larger than adimension of the substrate.
 16. The apparatus of claim 15, wherein theprober further comprises on or more prober bars.
 17. A system fortesting electronic devices located on a large area substrate,comprising: a testing platform; a substrate support disposed on thetesting platform, the substrate support sized to receive a large areasubstrate; an end effector disposed within the substrate support adaptedto move the substrate relative to the substrate support; a probersupport coupled to the substrate support; and a plurality of testingdevices coupled to an upper surface of the testing platform, each of theplurality of testing devices having a test area, wherein the pluralityof testing devices are spaced to form a collective test area sufficientto test an entire length or an entire width of the substrate such thatthe testing devices are capable of testing the entire substrate as thesubstrate is moved in a single direction through the system.
 18. Thesystem of claim 17, wherein each of the plurality of testing devices hasan optical axis and the substrate is movable in a direction orthogonalto the optical axis.
 19. The system of claim 17, wherein the pluralityof testing devices include at least six electron beam columns.
 20. Thesystem of claim 17, wherein the plurality of testing devices are in asubstantially straight line.